IMPLEMENTATION MODULE VT52;

IMPORT ASCII;
FROM STextIO IMPORT WriteChar, WriteString;
IMPORT IO, termios, FIO;

VAR
  savedTerm : termios.TERMIOS;
  flushFlag : INTEGER;
  haveTerm : BOOLEAN;

PROCEDURE Esc(c : CHAR);
BEGIN
  WriteChar(ASCII.esc);
  WriteChar(c);
END Esc;

PROCEDURE EnterAnsi; BEGIN Esc("<"); END EnterAnsi;
PROCEDURE SetAltKeypad; BEGIN Esc("="); END SetAltKeypad;
PROCEDURE SetNumKeypad; BEGIN Esc(">"); END SetNumKeypad;
PROCEDURE SetGraphics; BEGIN Esc("F"); END SetGraphics;
PROCEDURE SetAscii; BEGIN Esc("G"); END SetAscii;

PROCEDURE CursorUp; BEGIN Esc("A"); END CursorUp;
PROCEDURE CursorDown; BEGIN Esc("B"); END CursorDown;
PROCEDURE CursorRight; BEGIN Esc("C"); END CursorRight;
PROCEDURE CursorLeft; BEGIN Esc("D"); END CursorLeft;
PROCEDURE CursorHome; BEGIN Esc("H"); END CursorHome;

PROCEDURE CursorPosition(row, col : CARDINAL);
BEGIN
  WriteChar(ASCII.esc);
  WriteChar("Y");
  WriteChar(CHR(row + 31));
  WriteChar(CHR(col + 31));
END CursorPosition;

PROCEDURE ReverseFeed; BEGIN Esc("I"); END ReverseFeed;
PROCEDURE ClearToEndOfLine; BEGIN Esc("K"); END ClearToEndOfLine;
PROCEDURE ClearToEndOfScreen; BEGIN Esc("J"); END ClearToEndOfScreen;

PROCEDURE Identify; BEGIN Esc("Z"); END Identify;

PROCEDURE IdentifyResponse;
BEGIN
  WriteChar(ASCII.esc);
  WriteChar("/");
  WriteChar("Z");
END IdentifyResponse;

(* Terminal input mode (cf. Editor/Tests/T17.mod): Unbuffered
   saves the termios state and disables line buffering so device
   replies can be read char by char; Buffered restores it. *)
PROCEDURE Unbuffered;
BEGIN
  flushFlag := termios.tcsflush();
  savedTerm := termios.InitTermios();
  haveTerm := termios.tcgetattr(FIO.StdIn, savedTerm) # -1;
  IO.UnBufferedMode(0, TRUE);
  IO.UnBufferedMode(1, TRUE);
END Unbuffered;

PROCEDURE Buffered;
VAR res : INTEGER;
BEGIN
  IO.BufferedMode(0, TRUE);
  IO.BufferedMode(1, TRUE);
  IF haveTerm THEN
    haveTerm := FALSE;
    res := termios.tcsetattr(FIO.StdIn, flushFlag, savedTerm);
  END;
END Buffered;

END VT52.